The mineral deposits in the Guanajuato area are classic fissure-hosted low-sulphidation epithermal gold-silver-bearing quartz veins and stockwork. Mineralization of economic importance consists of fine-grained disseminations of acanthite, electrum, aguilarite, and naumannite with accessory pyrite, and relatively minor sphalerite, galena, and chalcopyrite. Gangue minerals include quartz, calcite, adularia, and sericite. The veins are accompanied by hydrothermal alteration consisting of argillic, phyllic, silicic, and propylitic facies. Mineral textures in this zone are typically fracture-filling, drusy, and coliform masses. At Guanajuato, Cenozoic volcanic and volcanogenic sediments unconformably overlie the Mesozoic basement rocks. In the area, the oldest Cenozoic unit is the Paleocene Comanja granite, (66 Ma – 56 Ma), this was followed by the Eocene extrusion of andesite (56 Ma – 33.9 Ma) which was sporadically deposited and contemporaneous with the deposition of the Guanajuato conglomerate in localized grabens. The Guanajuato conglomerate underlies an unconformity beneath a sequence of felsic to mafic volcanic rocks that consist of Oligocene ignimbrites, lava flows and domes (33.9 Ma – 23 Ma). The best mineralization is often found related to bends in the Veta Madre orientation (Barclay, 2007 and Rhys, 2013) such as at San Vicente in the Rayas area, and at Cata and Santa Margarita. These structural bends may be due to changes in rock type competencies, and varying thickne ........

The Guanajuato Mine Compleex (the “GMC”) comprises the Guanajuato and San Ignacio operations. Typically, all zones at the GMC are extracted by the Cut & Fill mining method.

Guanajuato consists of a series of interconnected, previously independent, mines including Promontorio, Santa Margarita, Rayas, Los Pozos, Cata, Valenciana and Guanajuatito.

Mining at Guanajuato predominantly comprises cut and fill stoping, with some pillar recovery in historic workings, and a few zones where mineralized extensions are discovered and mined over a period of a few months. Mining is generally more selective using jacklegs. However, where possible, mechanized cut and fill is utilized.

Two main shafts serve access to the active mine areas, while several other old shafts provide ventilation support. The Rayas shaft is used for transportation of personnel and supplies, while the Cata shaft, located just above the processing plant is used to transport the mineralized material for milling. These are currently de-energized and access of men and materials and egress of ore is via the Rayas ramps, San Vicente and Guanajuatito that provide the access at each end of the mine network, including for mobile equipment.

Mining is conducted by contractors, primarily sourced from nearby communities, utilizing equipment owned by the Company and the contractors. Mine contractors and equipment are alternated between the mines, including San Ignacio, to accommodate the ........

Crushing & Grinding Circuits
The ore from the 1,000-tonne capacity hopper is transferred along a 48-inch-wide belt to a 24 inch by 36-inch PettiBone jaw crusher where the 12-inch feed is reduced to less than 3-inch diameter. The feed from the jaw crusher exits along a 36-inchwide belt and feeds a 6 ft wide by 20 ft long double bed vibrating Ludowici screen. The Ludowici screen separates the feed by size with the upper bed separating material greater than 1 inch and the lower bed separating material less than ¼ inch. This ¼ inch “fine” material is then fed along a 24-inch belt to a hopper prior to grinding (currently feed on average of 88% less than ¼ to the mill). The over size from the Ludowici screen is fed to a Metso (300HP) secondary cone crusher for further size reduction which is then fed back to the Ludowici screen along a 24-inch belt to ensure the material is the appropriate size for the mill. The crushing circuit has a backup Simmons 5½ short head cone crusher that is utilized as needed.

Milling
Immediately after the crushing, the ore is stored in a series of "fines hoppers" which has a capacity of 1,800 tonnes. This material passes through chutes at the bottom of the hopper to feed three 24-inch-wide belts where the material is weighed (continuous weighing scale) and fed into three twin Denver of 7 ft by 14 ft ball-mills which are coated inside by a chromiummolybdenum alloy shield on the surface of the cylinder and natural rubber on the "heads". The grinding material used in these mills are 2.5-inch diameter high chrome alloy cast balls. The ¼ inch crushed material enters the ball mill where the movement, impacts and attrition from the balls promotes the wet pulverization of the mineral which is discharged by the mill as a "thick mineral pulp" where approximately 70% of the material by weight is solid and the remaining 30% is water. This thick mineral pulp is then diluted by adding water and feeds into 4 by 3-inch Krebs pumps where the material then feeds a series of Gmax G10 hydro-cyclone classifiers (two cyclones per mill) which carry out the classification of fines before entering the flotation circuit (75% of the material passing minus 200 meshes with automatic sampling). The average content of this material is 28% solid by weight and 72% water. The oversize material is returned to the mill for re-grinded in the closed circuit which has a "circulating load" of 350% thus ensuring the best release of the particles of interest. At this stage of grinding, reagents are added as the ore entersthe mills. This includes the addition of two specific reagents which promote the recovery of gold and silver (promoter MaxGold 900 and promoter 7310, both Cyteg brand products).

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